1. Field of the Invention
The present invention relates to a riding mower having a mower unit, a raising-and-lowering mechanism for vertically moving the mower unit, and the raising-and-lowering control lever which controls the raising and lowering mechanism.
2. Description of the Related Art
Examples of known riding mowers of the type mentioned above include ones with structures described in the following [1] and [2]:
[1] A riding mower having a structure in which a feedback operation is performed to shift the PTO speed change mechanism to neutral and to disengage the travel clutch as the lift arms reaches a predetermined height (JP Publication of Application No. H05-260837 (Paragraphs [0021], [0022], FIG. 5, FIG. 6)).
[2] A riding mower having a structure in which the raising and lowering control lever of the mower unit is returned to neutral and the PTO clutch lever for the PTO for driving mower is disengaged as the lift arms reaches a predetermined height (JP No. H06-133631 (Paragraphs [0011], [0012], FIG. 1)).
The riding mower described above in [1] uses a pivot plate which is pivoted as the lift arms reach the predetermined height, and a plurality of pivot members as cam followers which are pivoted in association with a movement of the cam portion formed in the pivot plate. And the riding mower is configured to provide a feedback of the movement of the lift arms by transmitting the movements of the plurality of the pivot members to the PTO lever and the clutch lever. With this configuration, since an upward movement of the lift arms is divided into two different directions using the pivot plate which functions as a cam and the pivot members which function as a plurality of cam followers, the structure as a whole is complicated and requires many components. And, the manufacturing process also requires a high degree of accuracy and assembling process is complicated and takes a great deal of time and efforts.
The riding mower described in [2] above is configured to feed back the motion of the lift arms to the PTO lever and the clutch lever by connecting a push-pull wire to the lift arms, and connecting the inner wire of the push-pull wire to the PTO clutch lever, and by connecting the outer wire to the raising-and-lowering control lever of the mower. Although structure is simplified by using the simple push-pull wire as a linkage structure with this configuration, since the force is transmitted by the abutting of the push pull wire with each lever, it is hard to set up a linkage timing with sufficient accuracy and the accuracy of the linkage may further decline by the elongation of the wire with the passage of time.